Field of the Invention
The present invention relates to a stacking device and an image forming apparatus.
Description of the Related Art
Some of image forming apparatuses such as a copier and a printer include a size detecting device which detects a size of a sheet stacked on a sheet feeding cassette containing a sheet on which an image is formed. As one of such size detecting devices, a configuration in which a size of a sheet in a sheet feeding tray is determined by detecting, with a sensor in a main body side, a detected plate which moves in accordance with a rear edge regulating unit configured to regulate a rear edge of the stacked sheet and be movable has been known. In the above-described conventional art, the detected plate having a length same as a moving amount of the rear edge regulating unit is required, and, since the rear edge regulating unit and the detected plate move integrally, a space in which the detected plate is able to move needs to have a size same as the moving amount of the rear edge regulating unit. Accordingly, there is a problem that a size of a device is increased in a size detecting mechanism described above. In order to solve this problem, Japanese Patent Laid-Open No. 2000-219326 discloses a configuration in which, by including a plurality of detected plates which are configured so as to overlap with each other, a space required for a movement of the detected plates is reduced.
However, in the configuration described in Japanese Patent Laid-Open No. 2000-219326, a level difference is generated between the detected plates due to the configuration in which the detected plates overlap with each other, and another mechanism for correcting an influence of the level difference becomes necessary. As a result thereof, there are problems such as complication of a size detecting mechanism and an increase in a region occupied by the size detecting mechanism in a main body side.